Scientific name: Polyommatus icarus

Male has blue wings with black-brown border and thin white fringe. Female brown, similar to Brown Argus, but with blue dusting near body.

The Common Blue is the most widespread blue butterfly in Britain and Ireland and is found in a variety of grassy habitats.

The brightly coloured males are conspicuous but females are more secretive. The colour of the upperwings of females varies from almost completely brown in southern England to predominantly blue in western Ireland and Scotland, but the colour is variable within local populations with some striking examples. Unlike Adonis and Chalkhill Blues, the dark veins do not extend into white fringes of wing margins.

It remains widespread but there have been local declines within its range.